The invention relates generally to a hammer attachable to a hammermill, or a tub grinder, or the like. More specifically, the invention relates to a hammer with the hammer body formed to extend the useful life of a rotatable hammer tip.
Impact crushers, like rotary hammermills or tub grinders, or the like, of the type contemplated herein, are widely used to size reduce objects into smaller fragments through rotation of a motor driven rotor. These devices typically include a plurality of hammers attached to the rotor, which strike the debris thereby causing the size reduction. The prior art describes uses of two piece hammers that comprise a hammer body and a rotatable hammer tip (see U.S. Pat. No. 5,285,974). Utilizing the rotatable hammer tip comprises a quick and convenient means for replacing an impacting working edge of the hammer tip. When the working edge of the hammer tip wears out, the hammer tip simply rotates through removal of securement bolts enabling operation to continue.
While the working edge of the hammer tip receives the brunt of the impacting force, the non-working edge of the hammer tip often comes into substantial residual contact with the debris. This can reduce the effective life of the non-working edge by anywhere from 25 to 50 percent or more. In other words, residual deflected contact with debris by the non-working edge of the hammer tip unnecessarily exposes the non-working edge of the rotatable hammer tip to wear and tear, and shortens the life of the non-working edge after rotating the rotatable hammer tip. This essentially reduces the life of a rotatable hammer tip, increases the cost of operation, and increases down time by requiring more frequent replacement of the rotatable hammer tips. Additionally, residual impact can also damage the securement bolts that attach the rotatable hammer tip to the hammer body.
Accordingly, for the foregoing reasons, a need exists for a hammer that utilizes a rotatable hammer tip that reduces premature wear and tear on the non-working edge of the hammer tip.